Internal-combustion engine glossary

Internal-combustion engine glossary
Each engine part has its own particular function to perform and in conjunction with other parts, equally as important, comprises the assembly called the internal-combustion engine or, for short, combustion engine.

An understanding of the operation or functions of the individual parts is necessary for a better understanding of the whole engine.

A person who intends to work in the diesel-engine field must know how to recognize the engine parts by sight and must learn their correct names and also their particular functions.

In Figs. A-1and A-2 are shown cross-sectional views of a diesel engine of the heavier type. In Fig. A-1 the section of the cylinder head is taken through the injector, or spray nozzle, and starting-air valve, whereas Fig. A-2 is a section one vertical plane through the center line of the engine and in the cylinder head shows the intake and exhaust valves.

In Fir. A-3 is shown the cross section of a diesel engine that is used in the automotive transportation field. Attention is called to the difference in the general construction of these two types of engines.

The following glossary of terms gives the student a preliminary understanding of the component parts used in the diesel engine and their functions as well as an explanation of some basic units and definitions of a more theoretical nature but indispensable to a person who wants to work intelligently in the chosen field and to rise from apprentice to engine operator and possibly to chief engineer of a large plant.

The way to use the drawings and the glossary is to study the drawings and to look up in the glossary every part name for explanation.

However, even a man familiar with diesel engines should have some use for the glossary looking up terms, units, and occasionally a definition to make sure that he remembers them correctly. Knowledge confirmed by an authoritative source is the best knowledge a person may have.

Absolute pressure. The pressure in pounds per square inch, psi, above absolute zero pressure, or perfect vacuum. A Bourdon or mercury gauge registers the difference between the pressure within a receiver and that of the outside atmosphere. At sea level and under standard barometric conditions, the atmospheric pressure is 14.7 psia. Tofind the absolute pressure, add 14.7 to the gauge reading in psig.
Absolute temperature. The temperature above absolute zero. If a Fahrenheit thermometer scale is used, absolute zero is Ч460 deg. To find the absolute temperature, add 460 to the Fahrenheit reading.
Accelerate. To increase the speed of movement, such as increasing the speed of a piston or flywheel.
Acceleration. The rate at which the speed of an object increases.
Adiabatic. From the Greek word meaning Уno pass through.Ф Adiabatic compression or expansion of a gas is accomplished without the loss or gain of heat through the cylinder walls.
Advance. Sometimes referred to as lead, or angle of advance, meaning the distance ahead of top or bottom (lead center of the piston as measured in degrees of crank travel.
Air cell. A small receptacle communicating with an engine cylinder into which some of the compressed air is forced, and from which air later flows back into the cylinder.
Air filter. A device for filtering the air, before it goes into the engine, to prevent particles of dust from entering the engine.
Air injection.